C. diff has overtaken MRSA as the leading hospital-associated infection and has been becoming more prevalent in the community as well and more virulent strains have emerged. But even as the Society for Healthcare Epidemiology (SHEA) and the Infectious Diseases Society of America (IDSA) have issued new guidelines for C. diff, new studies are showing promising measures to control this serious threat.
The new SHEA/IDSA guideline on C. diff appears online on the Infection Control and Hospital Epidemiology website (to be published in print in May 2010). The guideline does a good job of letting healthcare workers not only know what to do, but also what not to do. Importantly, testing for C. diff or its toxins should only be performed on diarrheal stools (unless ileus due to C. diff is suspected). Specifically, you should not test asymptomatic individuals for C. diff nor should you test to see if you’ve cured the infection and you should not perform routine environmental screening for C. diff. Stool culture remains the most sensitive test but is a slow method of detection. Testing for toxins A and B are more rapid but less sensitive. A 2-step method of testing (using enzyme immunoassay for C. diff glutamate dehydrogenase (GDH) first, followed by cell cytotoxic assay or toxigenic culture if the GDH is positive) may be the best strategy. Ultimately, PCR testing will likely become the best test. Repeat testing during the same bout of diarrhea is not recommended.
Prevention remains the best strategy for reducing the impact of C. diff infections. Good hand hygiene compliance is critical. Washing hands with soap (or antimicrobial soap) and water is important for both healhcare workers and visitors after coming in contact with infected patients. Contact precautions should be used as long as the patient has diarrhea and patients should be kept in private rooms (or cohorted if private rooms are not available).
Identification and removal of environmental sources should be undertaken. Electronic thermometers should be replaced with disposable ones. Chlorine-containing cleaning agents or other sporocidal agents should be used on the environment. Most important is minimizing the use of antimicrobial agents. A good antibiotic stewardship program is recommended but use of probiotics is not recommended at this time.
Cessation of antibiotics that may have facilitate development of C. diff infection is usually the first step in treatment of infected patients. Treatment should be guided by stratifying patients into mild-to-moderate and severe categories. Though there has been some development of resistance, metronidazole remains the usual drug for initial cases of mild-to-moderate disease. Vancomycin is used in initial cases of severe disease and both drugs may be considered in cases of severe complicated disease. Doses and route and duration are described in the guideline. Recurrent bouts are common and the guideline has recommendations for the best approaches, again stratifying by disease severity. Colectomy may be required in severe cases and serum lactate or peripheral white blood count may be useful in making a decision for colectomy. The guideline provides extensive documentation of the evidence base and bibliographic resources.
In the meantime, researchers at the Mayo Clinic demonstrated a significant reduction in the rate of hospital-acquired C. diff by consistent daily cleaning of high-touch surfaces with a sporocidal bleach disinfectant wipe for all patients in high epidemic areas.
Stobbe M. Study: Lesser-known bug a bigger hospital threat. Associated Press March 20, 2010
Cohen SH, Gerding DN, Johnson S, et al. Clinical Practice Guidelines for Clostridium difficile Infection in Adults: 2010 Update by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA)
Infection Control and Hospital Epidemiology 2010; 31(5): 000-000 online first March 22, 2010 http://www.journals.uchicago.edu/doi/pdf/10.1086/651706
Clostridium Difficile Infection Nears Zero: Intervention Drops Hospital Infection Rate By 1/3. Medical News Today. March 22, 2010.